[HN Gopher] Rapid colonization of a space-returned Ryugu sample ...
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Rapid colonization of a space-returned Ryugu sample by terrestrial
microorganism
Author : f1shy
Score : 115 points
Date : 2024-11-25 18:19 UTC (4 days ago)
(HTM) web link (onlinelibrary.wiley.com)
(TXT) w3m dump (onlinelibrary.wiley.com)
| bastih wrote:
| Color me a bad reader: what does this mean? The abstract pretty
| much leaves me in the abstract.
| jcoc611 wrote:
| > The presence of terrestrial microorganism within a sample of
| Ryugu underlines that microorganisms are the world's greatest
| colonizers and adept at circumventing contamination controls.
| The presence of microorganisms within space-returned samples,
| even those subject to stringent contamination controls is,
| therefore, not necessarily evidence of an extraterrestrial
| origin.
|
| Basically that preventing terrestrial contamination of
| extraterrestrial samples is super tough, and in the specific
| case of Ryugu the study concludes that contamination did occur.
| hn_throwaway_99 wrote:
| I recall a study from a few years ago that showed that
| Acinetobacter bacteria can eat the detergents that NASA used
| to clean spacecraft to prevent contamination: https://www.the
| atlantic.com/science/archive/2018/06/bacteria...
| swagasaurus-rex wrote:
| The samples mined from the Ryugu asteroid were contaminated by
| earth microorganisms some time between sampling and analysis.
| That makes it hard to tell the difference between potentially
| alien microorganisms and just regular earth microorganisms
| jfengel wrote:
| Which is why I'd just as soon we waited a few extra decades
| before landing people on Mars. We're chock full of bacteria
| and they will surely get out. Unlike robots we can't be
| sterilized.
|
| Once we can be certain that there is no native life, go nuts.
| Until then it's an irreplaceable bit of data.
| pavel_lishin wrote:
| Even robots cannot be sterilized; we've likely already
| infected Mars with some form of life. (Although, it's not
| likely that it's gonna spread far - it's a wildly hostile
| world.)
| eru wrote:
| Agreed. And Mars isn't even a good target for colonisation.
| Venus and even Mercury are better, but constructing space
| habitats is even better.
|
| On Venus, the surface is crazy hostile, but the atmosphere
| is so dense big balloons filled with a nitrogen / oxygen
| mixture, aka breathable air would float rather nicely, and
| at a height with pretty liveable temperatures.
|
| Mercury's surface has extreme temperature variations
| between night and day. But if you dig underground---which
| you would want to do anyway for meteor protection---you'll
| find that the variations average out, because large amounts
| of rock are a good heat buffer. Models suggest that near
| the poles there are underground regions with nice and
| liveable average temperatures.
|
| Solar energy is obviously much stronger at Venus's distance
| from the sun than for Mars.
|
| On Mercury, thanks to the consistent temperature
| variations, you could probably set up your standard issue
| steam turbine power plant fairly easily, just your sources
| of heat and cold would be a bit more interesting than on
| earth.
| harshreality wrote:
| What's the point of all that effort if those habs are
| going to be one-way trips for the people going there?
| What are they going to accomplish in their floating or
| underground habitats? They're not getting back to
| anywhere useful from either place. They're not going to
| survive without frequent Earth resupply[1]. Whether habs
| could exist is an interesting thought experiment, but
| that's all it is for the foreseeable future.
|
| Even a sizable Mars colony probably won't survive without
| frequent Earth assistance. The Mark Watney fantasy of
| growing food in Martian dirt with a little added
| fertilizer: mostly debunked[2]. The most sustainable case
| --for the foreseeable future--is probably a
| Biosphere2-like environment, where everyone hopes there's
| no accident, sabotage, or environment-caused damage. How
| many Starship missions would it take to get enough
| materials to Mars to build one Biosphere2 to support 8
| people?
|
| I agree with you that meaningful colonization of Mars is
| not serious. I just think the prospects on the inner
| inner planets are even more absurd than on Mars. In a
| floating Venusian hab, you could generate breathable air
| and not much else. Underground on Mercury, getting
| breathable air might be a problem, but you can import--at
| great cost, that delta-v is brutal--anything you can fit
| on a suitable rocket.
|
| There's no point to any of this except as research
| stations or jump-off ports, and for that Mars is the
| obvious choice: we can make hydrocarbon fuel there, and
| the surface isn't equipment-melting. But where would we
| be jumping off to? We have nothing planned, and no
| particular reason, to send humans to Europa or anywhere
| else.
|
| [1] How do you resupply a floating habitat on Venus? Even
| if you could, the constraints and resource limitations of
| a floating hab would be even more severe than for an
| underground, resource-poor Mercury hab.
|
| [2] https://www.sciencenews.org/article/mars-farming-
| harder-mart...
| gambiting wrote:
| I've been saying this for ages - if you want to see if
| humans can survive in a completely sealed underground
| habitat(and it would have to be underground on Mars),
| just try building one at the bottom of the ocean.
|
| And if you want a permanently occupied base in
| space....put one on the moon first?
| lmm wrote:
| There are zillions of Mars-like planemos in the galaxy -
| hell, there are 4 pretty similar ones just in our solar
| system. But Mars is the only one close enough to colonise.
| And if we don't colonise Mars, we'll probably never get far
| enough to study any of the others.
| asdff wrote:
| You can still tell the difference through dna evidence. In
| this case it would be like a ship returning with an alien
| book, a worker left an earth based book, you have no clue
| what book is which but one book shares 99% textual similarity
| with the king james bible. That one probably originated on
| earth.
| plxxyzs wrote:
| Basically microorganisms were able to grow in a sterile
| asteroid sample faster than previously anticipated. So just
| because there are signs of life in a recently fallen meteorite
| is less likely to mean there are space bacteria on it.
| pvaldes wrote:
| We should expect that, as the area is miraculously devoid of
| competitors, poisoners like fungus and predators. Those
| bacteria are the first colonists.
|
| Now we can wait for a colon bacteria colonizing this space
| turd and the jokes will write itself.
| theamk wrote:
| they got asteriod samples, and turns out that Earth bacteria
| grow great on them. It's a problem because from now on, if a
| evidence of life is discovered on sapce samples there is always
| a suspicion it could be contamination.
|
| https://news.ycombinator.com/item?id=42268396
| alganet wrote:
| It means the sample was spoiled. We can't exactly use it to
| understand the possibility of extraterrestrial life or life's
| building blocks.
|
| But since they were very careful, it is still useful to
| understand other meteorites and how they could have been
| contaminated as well.
|
| It also serves to predebunk anyone who would want to imply that
| those microbes were of alien origin.
| downrightmike wrote:
| Okay, refine procedures and try again
| londons_explore wrote:
| > opened in nitrogen in a class 10,000 clean room
|
| Since these samples were collected in a vacuum, doesn't it make
| sense to keep them in a vacuum, at least for science that
| requires the smallest possible amount of contamination?
| dredmorbius wrote:
| Nitrogen gas is for most purposes chemically and organically
| inert, particularly in the absence of oxygen.
|
| It's also abundant, cheap, and non-toxic, so long as the
| surrounding environment has sufficient oxygen that leaks don't
| put personnel at risk. Glovebox construction and use is also
| much easier than with vacuum.
|
| A positive-pressure nitrogen environment will also limit
| infiltration of oxygen or other contaminants, something which
| cannot be said of vacuum chambers.
|
| Past experiences (see Nasa SP-88 below) show that vacuum
| handling provides few if any benefits and numerous risks and
| complexities.
|
| Nitrogen-flooded environments can be made arbitrarily large,
| again a characteristic that's not true of vacuum chambers.
|
| A StackExchange question addresses this topic in more depth:
|
| <https://space.stackexchange.com/questions/29727/why-does-
| nas...>
|
| That sources a 1965 Nasa document: "NASA 1965 Summer Conference
| on Lunar Exploration and Science"
| <https://www.lpi.usra.edu/lunar/documents/65_lunar_conf.pdf>
| [PDF] (NASA SP-88). See p. 255.
| madaxe_again wrote:
| As per the article, however, a nitrogen atmosphere does not
| preclude growth of Bacillus, many species of which can
| tolerate a pure nitrogen atmosphere quite readily.
|
| That said, bacillus can survive hard vacuum too through
| sporulation, so short of analysing these samples in-situ,
| it's going to be really hard to prove an ET origin for any
| microorganisms.
| dredmorbius wrote:
| Where specifically are you getting that information?
|
| From TFA:
|
| _The nitrogen atmosphere, in which the sample was stored
| during this time, can be a bactericide for some, but not
| all, Bacillus species owing to the reduced water activity
| associated with the dry atmosphere (Munsch-Alatossava &
| Alatossava, 2014). The bactericidal effects of such
| atmospheres are not restricted to Bacillus, and thus
| provides no diagnostic information._
|
| That is: nitrogen should _generally_ kill bacteria, but
| _may not_ in the case of some Bacillus species. That 's
| quite some distance from saying the bacteria would _thrive_
| in that environment, and I 'd presume other factors (light,
| food supply, some means for oxidation) would be necessary,
| most of which could be reasonably constrained within a
| sample-examination environment.
|
| Origin determination might be made through C14 or other
| dating --- any extant _in situ_ bioactive materials would
| presumably be comprised of primordial carbon with
| effectively no C14 signature, as opposed to any recently-
| deposited or growing organisms.
|
| One challenge seems to be that there was very little
| Bacillus present, 11 to 147 individuals, which seems to
| have made DNA analysis impractical and would likely
| challenge isotopic analysis as well.
|
| NB: Not my area of expertise, just close reading, general
| understanding, and some research-fu.
| ta988 wrote:
| Because any leak would bring external material inside. Whereas
| slightly overpressured nitrogen keeeps the outside world away.
| metalman wrote:
| occurs to me that sample return missions should ,not end up ON,
| earth, but in orbit where they could be retrieved and studied
| initialy, befor bieng packaged for earth landing, therby vastly
| limiting any possible cross contamination, and having a pristine
| storage environment for control samples
| porphyra wrote:
| Yeah but spacecraft themselves being contaminated is a real
| possibility.
|
| NASA found that some bacteria can metabolize isopropyl alcohol
| [1]
|
| [1]
| https://www.theatlantic.com/science/archive/2018/06/bacteria...
| tomrod wrote:
| I'd prefer we seed life where we go, but I know that's
| against some others philosophy
| api wrote:
| I am not opposed to it in most cases for any moral reason,
| but if we did accidentally contaminate an example of even
| incredibly simple ET life it would be an enormous
| scientific loss. What one second example of life could
| teach us would be massive. Contamination would mean we
| could never be sure we were studying the authentic thing.
| mock-possum wrote:
| Yeah if there's no life there already, then we should
| probably go ahead and put it there and see what happens.
|
| We'd have to be real sure that there's no life there
| already though.
| gambiting wrote:
| That's kinda impossible though, given the variety of
| environments we find life in on Earth - there are
| microbes living miles under the surface, on massively
| radioactive spent nuclear fuel, inside thermal vents that
| reach hundreds degrees celcius....in fact I bet there
| isn't any environment on Earth that doesn't have some
| form of life in it, other than artificially created by
| us.
|
| There is an argument that Mars probably already has life
| on it, as many of the probes we've sent almost certainly
| brought something with them despite our efforts to
| sterilize them.
| 7952 wrote:
| It would certainly be interesting to see what survived.
| muny wrote:
| I'm not super familiar, but I think a "Class 10,000" clean room
| is actually quite on the "dirty" end of the clean room spectrum.
| Perhaps they figured this had a low likelihood of being the
| source of domestic microbes?
| madaxe_again wrote:
| Correct. As per the paper the population of organisms suggests
| contamination occurred during sample preparation at the Natural
| History Museum.
| nis0s wrote:
| It seems then sample analysis should happen in place instead of
| bringing samples back to study. I think this motivates the need
| for better ISS equipment, or off-site research labs, like on the
| moon.
| eru wrote:
| The ISS is crawling with bacteria, too. Anything that humans
| touch, does.
|
| > [...] or off-site research labs, like on the moon.
|
| Why stick your lab in a gravity well? And why involve humans
| (as anything closer than remote operators of robotics)?
| pvaldes wrote:
| Hum, I didn't though about it. Are you saying that there are
| life in Mars yet, in each place that the Rover visit?
| asdff wrote:
| There is a reason they send rovers in places they expect to
| find ancient life and not present day life.
| pantalaimon wrote:
| > The ISS is crawling with bacteria
|
| I have read that the smell must be quite peculiar, it's not
| like you can clean that thing.
| schiffern wrote:
| By that standard, any room you've even been in is "crawling
| with bacteria." The ISS is cleaned constantly, with a
| deeper cleaning once per week.
|
| I think any odors would be more related to using dry
| toilets, stretching clothing in the absence of laundry
| facilities, and hosting a gym (2 hours exercise per day per
| crewmember) with no shower. No Rinse Body Bath only goes so
| far.
|
| https://www.youtube.com/watch?v=JUUvlnnVMSQ
| AYBABTME wrote:
| Consequence: we'll find life wherever we go, and we'll never know
| if it was always there or if we brought it there?
| bglazer wrote:
| For the second part, we'd be able to do biochemical assays like
| mass spectrometry and discover immediately that the "alien"
| life was made of the same proteins as Earth life. Gene
| sequencing would then confirm a match to a known microbe, or at
| least to a family of them.
|
| Now, we could argue that panspermia would predict that alien
| life in our solar system might be similar to earth's species,
| but we would expect to see some radical differences, even at a
| cursory first look, given the total isolation of the two life
| systems for (presumably) billions of years. All that to say
| that it would probably be quite easy to discern whether a
| microbe is definitely earth life.
| kombookcha wrote:
| I suppose the much more bothersome scenario is finding a
| microbe that is ambiguously novel, and doesn't neatly fit any
| particular family of Earth microbes, but also isn't radically
| different enough to be confidently classified alien.
|
| Like did we accidentally discover an eccentric and rare Earth
| microorganism that thrives in this unusual environment, or is
| it an honest to god extraterrestrial and life in both spheres
| just happens to converge along certain lines by evolutionary
| convenience or chemical necesssity? How would we tell?
| stouset wrote:
| Alien samples won't have carbon-14, which is created in the
| atmosphere.
| AYBABTME wrote:
| Why not?
| asdff wrote:
| You'd sequence this organism. If it came from earth you
| could tell. People would have either sequenced it already
| or a distant relative species where you could compare
| sequence divergence and when they shared a last common
| ancestor. Convergent evolution might lead to similar
| phenotypes but the actual sequence of genes involved is
| only going to be similar if those genes shared an
| evolutionary history.
| bglazer wrote:
| Chemical space is very very large. Like we can say for
| certain that only a very tiny percentage of all possible
| synthesizable organic molecules have ever existed in our
| universe. The combinatoric explosion is just so enormous
| that I think its incredibly unlikely that the only
| configuration of molecules that supports life is our own
| here on Earth. In fact, I think we know this given that
| there are artificial amino acids that can be incorporated
| into our existing protein biochemistry without a problem.
| Thats a small example but it points to a much larger space
| of chemical compositions that can support life. So an
| entirely separate evolutionary process would almost
| certainly land in a very different chemistry for things
| like information storage and molecular machines like
| protein.
|
| Also our biochemistry is compositional, it takes small
| building blocks and remixes and combines them to build
| larger structures. I suspect that this is also a necessary
| feature of life in general. It's very hard, basically
| impossible, for natural evolution to build huge structures
| like proteins just by pure uniform random selection.
| Instead it takes small pieces randomly, then puts them
| together to get complex life.
|
| Point being, its a very very path dependent process. Any
| small difference in the early building blocks gets
| exponentially magnified when evolution uses those blocks to
| build life. So that leads to easily detectable, drastic
| differences in biochemical structure. This is evident on
| earth in that our biochemistry has a feature called left
| handed chirality that seems to be a purely random accident
| of the very earliest steps of life. That then was
| transmitted to every living being on earth. There's
| probably a fifty-fifty chance that extraterrestrial biology
| is right handed instead. Every step in evolution also
| probably has random accidents just like that. Our
| particular biochemistry is the result of a trillion coin
| flips. There are probably many other biochemistries that
| work just fine, but look way different
| JumpCrisscross wrote:
| > _How would we tell?_
|
| You'd send a second mission to do analysis _in situ_.
| ngneer wrote:
| I suppose we need a one-way valve, such that information about
| the sample can flow to us while nothing can affect the sample.
| Conceptually like a Heimlich valve. Or, as a wild alternative,
| we could amplify the signal in some way, perhaps using sterile
| equipment in space, such that any Earth life would drown out in
| alien life and contamination would no longer pose as big an
| issue.
| vasco wrote:
| Depends, if you don't take anything big with you and see a dog
| walking around you can tell the difference.
| asdff wrote:
| No you can sequence these organisms and see where they came
| from. If you brought them from earth vs if they were not from
| earth would be apparent in genetic analysis.
| ngneer wrote:
| That's really too bad. I liked the notion that RNA found on Ryugu
| was brought back by Hayabusa. It feels a smidge lonelier down
| here on planet Earth. I imagine contamination prevention
| protocols will be revised.
| permo-w wrote:
| this paper would do well to specifically define the term "space-
| returned" or use clearer terminology
| verzali wrote:
| It is literally a sample that was collected in space and
| returned to Earth on Hyabusa 2.
|
| > Sample A0180 is a 1 x 0.8 mm regolith particle collected by
| the JAXA Hyabusa 2 mission to asteroid 162173 Ryugu. Samples
| were collected from Ryugu during close passes of the spacecraft
| by capturing surface particles during two touchdown events,
| with the second touchdown occurring after the use of kinetic
| impactors to reveal subsurface materials. Sample A0180 was
| recovered in the first collection attempt. The particles were
| transported to Earth in a hermetically sealed chamber that was
| opened in nitrogen in a class 10,000 clean room at JAXA (Yada
| et al., 2022). Individual particles were picked with sterilized
| tools and placed in airtight containers under nitrogen for
| distribution to participating science teams. Prior to study the
| Ryugu samples had no exposure to the terrestrial environment
| and the JAXA contamination control protocols were of the
| highest standard (Yada et al., 2022).
| deadbabe wrote:
| Does this mean maybe we should just load up micro organisms onto
| probes and fire them off onto passing asteroids in hopes someday
| they will hit some planet somewhere and spawn new life after
| millions of years?
| asdff wrote:
| A far more realistic prospect of backing up life on earth than
| using humans for sure
| BuyMyBitcoins wrote:
| One thing to consider is that even though bacteria _can_
| colonize some sterile object, they don't seem to be able to
| create their own self sustaining biome. As far as we know there
| are no species that can truly exist independently without any
| resources generated from some other species.
|
| Which makes sense because full autonomy would be more costly
| than simply relying on organic products made by some other
| species in the biosphere. For instance, all Vitamin B is
| produced by bacteria and more complex organisms depend on it as
| a nutrient rather than producing it on their own.
| xeonmc wrote:
| For some reason I thought the title was in reference to the
| folklore legend of Urashima Taro where upon his return from Ryugu
| he unsealed the forbidden treasure box resulting in rapid aging
| of him into an old man, and that the article is discussing the
| role of microorganism contamination in such a phenomenon.
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